Although our 6 speed S-max will pull our caravan up most motorway inclines in 5th (2100rpm/60mph)we leave it in 4th(2700rpm/60mph) so cruise control stays on and we get an extra 2mpg as the engine is under less load
also another good thing about cruise is when the datasets are programmed into the engine ecm ,the ecm is told to make more power when cruise is enabled.thus incoureging it to be used.